Abstract The construction of efficient semiconductor/cocatalyst heterojunction is a promising strategy to promote the photocatalytic H2-production efficiency from water reduction. Herein, a novel Cu2(OH)2CO3/Zn0.5Cd0.5S heterojunction composite with superior photocatalytic H2-generation activity and stability was prepared via a facile in situ synthetic route, in which Cu2(OH)2CO3 served as cocatalyst stimulating the photocatalytic H2-evolution performance of Zn0.5Cd0.5S. The Cu2(OH)2CO3/Zn0.5Cd0.5S heterojunction photocatalyst containing 5 wt% of Cu2(OH)2CO3 exhibited a prominent H2-evolution efficiency of 275.7 μmol h−1, which is superior to the noble metal Pt-modified Zn0.5Cd0.5S photocatalyst (237.3 μmol h−1) and much higher than bare Zn0.5Cd0.5S (90.8 μmol h−1). The active Cu+/Cu0 species generated during the photoreaction process is responsible for the prominent H2-production activity of the heterojunction photocatalyst, which plays triple roles in enhancing the photoactivity of Zn0.5Cd0.5S via accelerating the charge separation, decreasing the overpotential of H2-generation and improving the reduction ability of photoinduced electrons. Moreover, the formed Cu+/Cu0 species during photoreaction can be readily oxidized back to Cu2(OH)2CO3 upon exposure to air, thus restores the photoactivity and therefore enables good reusability of the Cu2(OH)2CO3/Zn0.5Cd0.5S heterojunction photocatalysts. This work provides a new insight into the fabrication of Cu2(OH)2CO3-assisted heterojunction photocatalysts with the highly stable and efficient performances for solar-to-chemical energy conversion.

中文翻译：

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深入了解 Cu2(OH)2CO3 助催化剂在提高 Zn0.5Cd0.5S 纳米粒子的光催化析氢活性方面的三功能作用

摘要 构建高效的半导体/助催化剂异质结是通过减水提高光催化制氢效率的一种有前景的策略。在此，通过简便的原位合成路线制备了具有优异光催化产氢活性和稳定性的新型 Cu2(OH)2CO3/Zn0.5Cd0.5S 异质结复合材料，其中 Cu2(OH)2CO3 作为助催化剂刺激光催化 H2 - Zn0.5Cd0.5S 的演化性能。含有 5 wt% Cu2(OH)2CO3 的 Cu2(OH)2CO3/Zn0.5Cd0.5S 异质结光催化剂表现出 275.7 μmol h-1 的显着析氢效率，优于贵金属 Pt 修饰的 Zn0。 5Cd0.5S 光催化剂 (237.3 μmol h-1) 远高于裸 Zn0.5Cd0.5S (90.8 μmol h-1)。光反应过程中产生的活性 Cu+/Cu0 物种是异质结光催化剂显着的产氢活性的原因，它通过加速电荷分离、降低 H2 的过电位，在增强 Zn0.5Cd0.5S 的光活性方面发挥着三重作用- 产生和提高光生电子的还原能力。此外，在光反应过程中形成的 Cu+/Cu0 物质在暴露于空气后很容易被氧化回 Cu2(OH)2CO3，从而恢复光活性，从而使 Cu2(OH)2CO3/Zn0.5Cd0.5S 异质结光催化剂具有良好的可重复使用性. 这项工作为制备具有高度稳定和高效的太阳能-化学能转换性能的 Cu2(OH)2CO3 辅助异质结光催化剂提供了新的见解。